When large quantities of hay are to be purchased, for cattle feed or the like, it is desirable to sample the bales of hay and determine the content of certain key ingredients including (1) moisture content, (2 ) protein content, (3) fiber content, and (4) content of lignin. In this regard, for example, a moisture or water content of 12 to 15% would be considered acceptable, while more than 18% would be undesirable, as the hay would be likely to mildew or otherwise spoil, because it had not been adequately cured or had been subject to excessive moisture prior to bailing. Also, for example, a level of protein in the order of 21%, would be desirable; but the availability to the cattle also depends on the amount of lignin present in the hay, as high levels of lignin indicate that the protein may be encapsulated by the lignin and thus may not be available for digestion and utilization by the cattle. In this regard, for example, a lower level of lignin in the order of 4 or 5% would be acceptable, while a higher level such as 71/2 or 8% might be so high that much of the otherwise available protein would not be available for utilization by the cattle.
Incidentally, the most common method employed for analyzing a hay sample is chemical; however, a near infrared reflectance analyzer may be used and these are available from a number of manufacturers including Technicon of New York.
In accordance with practices which have been employed heretofore, the hay probe units which have been used frequently have a relatively long tube, such as 2 or 3 feet in length, and a relatively large diameter, such as one inch. Also, relative small constant diameter tubes, in the order of one-quarter inch in diameter have been used. In addition, the samples have customarily been held in an inexpensive air permeable plastic bag or a paper bag, and delivered to a laboratory for analysis up to several days later. Also, because the amount of hay in the sample, as contained in the paper bag or the plastic bag, may vary substantially, the laboratory may have difficulty in selecting the volume of material necessary for analysis in a manner which will keep it representative of the whole sample. Likewise, the necessary preliminary grinding step may be very quick if the sample was taken with a small diameter probe because the fibers in the material have been cut to a short length. Conversely, if the sample was taken with a large diameter probe, the grinding step may take a proportionately longer time, even possibly to the extent of having to be done twice. Unfortunately, this has the effect of subjecting the hay to the ambient humidity conditions and the final measured moisture content may be significantly different from that which is actually present in the baled hay. In addition, when large diameter probes are employed, different amounts of hay are obtained from soft bales of hay than from hard packed bales of hay, because different levels of penetration of the probe occur. This varies the amount of material which is taken from each bale, and thus varies the resultant analysis. Also, sheets of paper are often included within the sample bags for identification purposes, and this will tend to alter the analysis, as the paper may absorb moisture from the sample.
From the foregoing description, it is evident that the prior techniques have left much to be desired, and the analysis results have related to the sample as ultimately tested in the laboratory, which often has had only a remote relationship to the material actually present in the bales of hay supposedly being tested. Accordingly, it is a principal object of the invention to provide a hay probe assembly and technique for obtaining standardized samples which will more accurately reflect the actual content of the hay being sampled than arrangements which have been used heretofore.